<?php
//
// FPDI - Version 1.2
//
// Copyright 2004-2007 Setasign - Jan Slabon
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
class pdf_context {
	var $file;
	var $buffer;
	var $offset;
	var $length;
	var $stack;
	
	// Constructor
	function pdf_context($f) {
		$this->file = $f;
		$this->reset ();
	}
	
	// Optionally move the file
	// pointer to a new location
	// and reset the buffered data
	function reset($pos = null, $l = 100) {
		if (! is_null ( $pos )) {
			fseek ( $this->file, $pos );
		}
		
		$this->buffer = $l > 0 ? fread ( $this->file, $l ) : '';
		$this->offset = 0;
		$this->length = strlen ( $this->buffer );
		$this->stack = array ();
	}
	
	// Make sure that there is at least one
	// character beyond the current offset in
	// the buffer to prevent the tokenizer
	// from attempting to access data that does
	// not exist
	function ensure_content() {
		if ($this->offset >= $this->length - 1) {
			return $this->increase_length ();
		} else {
			return true;
		}
	}
	
	// Forcefully read more data into the buffer
	function increase_length($l = 100) {
		if (feof ( $this->file )) {
			return false;
		} else {
			$this->buffer .= fread ( $this->file, $l );
			$this->length = strlen ( $this->buffer );
			return true;
		}
	}
}
?>